Manhole-cover.



' No. 790,562. PATENTED MAY 23, 1905.

J.IFA.DOIRSEY. I MANHOLE COVER.

APP LIOATION FILED FEB. 17.1906.

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No. 7eo,5c2.

UNITED STATES Patented. May 23, 1905.

JOHN F. DORSEY, OF PORTSMOUTH, VIRGINIA.

MANHOLE-COVER.

SPECIFICATION forming part of Letters Patent No. 790,562, dated May 23,1905.

Application filed February 17, mos. Serial No. 246,061.

.To all whom it may concern:

Be it known that I, JOHN F. DORSEY, a citizen of the United States,residing at Portsmouth, in the county of Norfolk and State of Virginia,have invented certain new and useful Improvements in Manhole- Covers andJoints, of which the following is a specification.

My'invention relates to manhole plates or covers and joints therefor.

The object of my invention is to provide manhole and hand-hole platesfor steam-boilers and the like that are incapable of having theirpacking blown out by pressure, which often happens with disastrousresults.

By my invention I am also enabled to make a joint and renew the packingthereof when the boiler or tank is full of water, which cannot beaccomplished with the devices now in use.

The invention will be more fully understood from the accompanyingdrawings, forming a part of this specification, in which Figure 1 is asectional elevation through the parts pertinent to my invention. Fig. 2is an elevation of the same with several members drawn apart. Fig. 3 isa plan of the plate and its packing. Fig. I is a plan of the compressionplate or disk. Fig. 5 is an enlarged part-sectional elevation showingthe details of the joint.

In the drawings, in which like referencenumerals indicate similar partsin all the views, 1 is the boiler or tank shell, through which anopening is made for the manhole or hand-hole in the ordinary manner.

2 is the plate, having a raised part 3, forming the flange 4;. The platehas a bolt 5 screwed into it and having threads the entire lengththereof and extends from the plate a suitable distance, as shown.

6 is a clamping disk or plate having a flange or rim 7 around it atright angles to the plane of the web or disk portion 6, and thereforeforms a dished or flanged depressed surface.

7, Fig. 4:, is an aperture for the passage of the bolt 5 and will befurther described hereinafter.

8 is a gasket of some compressible packing portion 3 of the plate 2. Theunited parts as above described are then inserted into the boilerthrough the opening provided for the purpose and the guard applied andsecured to the boiler by its nut.

9 is the clamping-nut for the packing and is located between the plate 6and the guard or dog 10 and is screwed up after the nut 11 is tightened.

Referring to Fig. 5, when the plate 6 is compressed by the nut 9 thepacking 8 is distorted and fills the very small clearance-space 12between the portion 2 and. the packing, preventing an escape of steambetween the shell 1 and the flange 7 of the disk or plate 6.

As shown, my invention provides for a joint made upon the manhole .orhand-hole plate, the packing not being located upon the inner surface,of the boiler or tank shell. Therefore the packing cannot be blown outand remains tight for all pressures, the maximum of which may be veryhigh without affecting the efficiency of thejoint.

t is usual to place the packing upon the flange of the plate and insertit into the boiler, the packing being next to the inside surface of theboiler-shell, so that they often blow out and leak. In my presentinvention I have provided means to make a safe and steamtight jointwhich is both cheap and eflicient and is confined to the edge of themanhole or hand-hole opening and not within the boiler.

I am not confined to the precise details shown in the drawings, as I maymake such changes as may be deemed expedient without departing from thesubject-matter claimed or sacrificing any of the advantages thereof.

Having described my invention, what I claim, and desire to secure byLetters Patent, is

1. An elliptical manhole-plate comprising a flanged independent memberand a dished member, a ring of rectangular or square packing upon theflanged member and compressed by the edges of the dished member, andmeans carried by both plates to expand the packing in one directionagainst the edges of the manhole.

2. An irregular manhole plate or cover comprising a flanged member andan interlocking member adapted to slip over the flanged memher, a ringof square or rectangular packing between the said members, a boltsecured to one member and movably passing through the other, and meansactuated by the said bolt to expand the packing against the edges of themanhole by the interlocking member in one direction.

3. A manhole 0r hand-hole plate having the flanged plate 2, theinterlocking member 6, the flange 7, the square or rectangular packing8, the clamping-bolt 5 and the guard or dog 10 substantially as shownand described.

In testimony whereof I have hereunto a1- fixed my signature, in thepresence of two witnesses, this 14th day of February, 1905.

JOHN F. DORSEY.

Witnesses:

WALTER B. BURROW, THOMAS M. BOYLE.

